First of all, let me say that I am a big fan of Celestia, following her development since 2003. This was my first space-sim that I loved and spent many days searching and using add-ons from Celestia Motherlode.

But over the years, it seems that Celestia's creators lost pace in implementing great changes and improvements to the program. From 2003-2008 things were good, and they promised that version 2.0 will come soon. From 2008 onward things slowed down and today we have version 1.6.1 which is, personally, not so much better than 1.4.1 which was released many years ago.

That was the days when I started search for a new space program, and then discover Infinity: The Quest for Earth and finally, in November 2011, probably best space sim to date, Space Engine.

Now, I know that many of you here are also fans of Celestia and came here for simmilar reasons, so don't take my words on harm's way. I can say that Space Engine is better and has better community and development and if things don't change, Celestia will be slowly forgotten in years to come, which is not something I would like to see happening.

I too started as a fan of Celestia, though not as early as you did, I started using it in 2008. It did look like development was going pretty well, I even followed dev emails on SourceForge. But yeah no later than when 1.6.0 came out they just kinda stopped. It's really sad, because it was such an amazing program, and really brought a lot of joy into my life and allowed me to explore my imagination by making my fictional universes come to life through my own addons and those of others.

I discovered SpaceEngine last year entirely by accident, I can't even remember where I saw it, probably just some website mentioned it and had a download mirror. Well eventually I came to seek out the actual website and found it, and it looked like such a wonderful community here that I decided to set aside my normally timid ways and actually participate on the forum. And I am so glad I did. Not only is SE a great program, but it is being made and supported by great people.

It is sad that Celestia is dying (or even already dead maybe), but it served its purpose and inspired other programs like this one, and its death will allow others to discover that there are even greater things out there than Celestia.

Even though SpaceEngine is superior to Celestia in almost every way, Celestia will always hold a special place in my heart, and at least for now I will still visit it from time to time because there are a few things left that Celestia has that SpaceEngine doesn't.

The creator of celestia aka Chris Laurel is currently working on some other project called "Cosmographia" it is for MacOSX system, but onto the subject now , Celestia was the first simulator that introduced me to the exploration of space and discovered my interest in it

I was overwhelmed for what a "simple" program could do back then (2003-4) but as the years passed technology of course evolved and they had to find a way to make the program to look like we are indeed in 2000's and to do that they had to implement their own engine graphics like SE does but they didnt want to so it stayed like a simple simulator that many users had lost their insterest in it it looked like just a plain boring Space Simulator after a period of time

So imho they should expected that , well yeah ok its one of the first simulator that ever came out but we live in 2012 we want more than just looking trajectories , orbits and how realistic it should things look like

Well this is my opinion for Celestia of course i had a lot of fun with it kept me awake a lot of nights , exploring , seeing and imagine how big the Universe could be and everything until i realised that they didnt want to evolve it and somehow i lost interest in it

I started with MPL3D Solar System wich is pretty awesome aswell and I love it (have to reinstall it again, I miss it :() Oh well then I found Celestia wich I particulary liked the galaxies, until I accidently got to one of ''kurtjmac'' his video's of Space Engine 0.9.4 I was inmediatly sold lol I also have Stellarium a more ground based telescope simulation. I'm trying to find more, but yeah SE is on N° 1 of all space simulations.

Here's my list of favorites (although I suck at making addons and such, actually have no idea how to it...)

So basically my top 5 favorites of a pure install:

1. Space Engine ofcourse... (SpaceEngineer FTW ) 2. MPL3D Solar System (had no idea about other simulations but you have to pay for this one... but it's really worth it) 3. Although I don't have Universe Sandbox it's still on my 3rd spot 4. Stellarium (ground based simulation) 5. Celestia

On the subjects of both Celestia and SpaceEngine, here is the result of my first attempt at importing procedural SE textures into Celestia (after a good deal of editing and work). I was rather impressed with the results, and I'm very glad that the export functionality exists in SE.

These screenshots were taken in an "unreleased" build of Celestia (5135), which had absolutely gorgeous star rendering (better than SE even I think) which were not sprite based like SE and other Celestia versions. To run a random motion script and fly though the stars in that build was such a dream ♥ I wasted at least a few hours just watching the stars fly by.

Celestia uses point sprites, which can be used in SE too (stars style option "points").

I use the "Points and sprites" option in SE as this gives the best visual appearance imo; all SE methods look better than the methods in all major Celestia releases. However that particular build of Celestia that I used above had a completely different shader-based method which was producing some fantastic results; its development thread was here: http://www.shatters.net/forum/viewtopic.php?f=10&t=16031 By page 2 they were starting to achieve some very impressive results.

I don't think they ever finished with it though, and there were some issues with transitioning into a star system, especially if it had a bright star; the star would look extremely bright and fill the screen, and then disappear as you crossed the 1 ly system boundary.

I don't think they ever finished with it though, and there were some issues with transitioning into a star system, especially if it had a bright star; the star would look extremely bright and fill the screen, and then disappear as you crossed the 1 ly system boundary.

I had the same issues in the early stages of development. Now I use logarithm of the star's real brightness, if it gets greater than some amount, this solves the problem, but makes the sky look unnatural if you increase limiting magnitude too much (bright stars becomes almost identical).

This is the educational version of Celestia: Celestia ED. It is a normal version of Celestia full with the best addons, which were ever created for Celestia. There are also educational activities in .pdf-format to support it. It has also the ability to play sounds while running like wind or warp drive noises. What you have seen in the video are textured stripes placed on invisble sphere, which rotates. This creates the impression, that there are moving solar flares and auroras. In the case of the volcanic activity at Io, I'm not sure. I think that was a particle effect.

I have spend a lot of time with it. I expecially loved the moving parts like accretion disks and the jets of neutron stars. That gaves the universe in Celestia something real and exciting. I'm looking forward to their implementation in Space Engine, because it is one of the last things, that Celestia have and Space Engine don't.

But the effects on the photos and the videos are looking better than in the real programm. It's a programm with old rendering methods and you can see this.

You can take a look at Celestia ED and its description here, if you are interested: